Core and related tube structure



Jan. 1, 1952 DANIELS 2,580,661

CORE AND RELATED TUBE STRUCTURE Filed Jan. '7. 1949 firm 12 525 IN V EN TOR.

Patented Jan. 1, I 952 UNITED STATES PATENT OFFICE 2,580,661 CORE AND RELATED TUBE STRUCTURE Harry Daniels, Brooklyn, N. Y., assignor to Super Electric Products Corp., Jersey City, N. J a corporation of New Jersey Application January 7, 194? Serial No. 69,802

2 Claims. (01. 171-242) The present invention relates to a novel and improved product and a method for making same, to be employed in the manufacture of electrical coils used in radio and television apparatus.

lhese coils are of the type comprising one or more bobbins of insulated wire wound on or mounted about a tube' of insulative material having a core made of powdered iron positioned therewithin and movable therealong, whereby inductance may be varied to accomplish a tuned circuit.

In a preferred embodiment of this product, the core may be a screw and the tube is thin walled, of paper-like material and provided with thread-engaging indentations so that the core and said tube be in threadedly engaging relation. More particularly, this invention concerns itself with said tube and core of novel and improved construction and with a method of treating tube and core components before assembly, in order to accomplish the following objects.

The principal object of this invention is to provide a tube and its core of novel and improved structure, and to provide a method to attain such structure, so that when said parts are in assembled engagement, and particularly when the core is a screw, said core will adhere to the tube and maintain itself against accidental displacement and yet provide for itself easy passage along the tube when manually turned with respect to the tube. It is to be understood that the same manner of structure and method to attain same is likewise applicable in embodiments where the core is slidable piston-like within the tube which carries the bobbins. As matter of illustration, the screw form of core is here chosen.

Another object hereof is to provide a novel and improved product structure and method of the nature mentioned, which permits movement of the core along the tubes interior, by application of torques, or forces, which are within normally desired limits.

A further object of this invention is to provide a novel and improved product structure and method of the character set forth, which are easy and cheap to accomplish and efficient to carry out the purposes intended.

Other objects and advantages will become apparent as this disclosure proceeds.

In the accompanying drawings forming part of this specification, similar characters of reference indicate corresponding parts in all the views.

Fig. 1 shows the longitudinal view of a tube and its associated core.

Fig. 2 is a top plan view of Fig. 1.

Fig. 3 is a longitudinal view of the core.

Fig. 4 is a diagrammatic view showing steps in the practice of the method herein to attain the structural make-up of tube and core in accordance with the teachings of this invention.

In the'clrawings, the numeral i5 designates a stiff, thin-walled tube of paper-like material, preferably having thread-engaging pro ections 16 pressed in its wall by any suitable means known in the art, or by use of a device as taught in my application for patent thereon, simultaneously filed herewith. The core I! is exteriorly threaded as a screw for engagement with the tubes interior and said projections l6, and capable of moving along said tube when axially turned with respect thereto. Said pIOJeCDlOnS lc are set, and the tube materially stiliened by a dried coating of electrical insulation varnish applied thereon. Of course, this coating is applied to the tube soon after the pro ections are formed, and baked dry before the core ii is inserted.

I have discovered that masses made of powdered iron may be impregnated with electrical insulation wax in a boiling bath of such wax. In this manner I have impregnated the core i7 and thus have given its structure the property that when engaged in the tube it, it adheres to its surface maintaining any set position and will not loosen until axially turned with respect to the tube l5, and because of its wax content will accomplish such adhesion while at rest within the tube, and offer a sort of lubricant for screw movement. No objectionable binding occurs, and normal reasonable torques accomplish core movement at any time.

As an example of the materials used, I mention their designations as known in the electrical manufacturing industries and in 0mm merce generally. The untreated tubing is Cos molite #1120 grade. The electrical insulation varnish is a product of Dolph, and the electrical insulation wax is Zophar Mills #769. Other electrical insulation varnishes and waxes and paper-like tubing known in this art, may be employed to build the final core and tube structures as hereinabove set forth.

I will now describe a practical process practiced in accordance with this invention, for the treatment of powdered iron cores ll, and the tubes I5 provided with interior thread engaging forms, so that said articles be of the structure and function as mentioned.

I have used tubes of 1/64 inch wall and inch inside diameter for a screw core of 2; inch outside diameter. Soon after the pressed-in thread engaging formations It were made, and

before such would start to relax towards initial rated drum 22, positioned within a heat cham-'.

ber 23. Said tubes were thusibaked dry and knocked against each other due to drum movement. Upon removal from the drum, the tubes were separated and apart from each other, and upon being cooled, were ready for receiving the cores H, which were subjected to a boiling bath of electrical insulation wax-at 24.

Heating in vessel 20 was for one hour at a temperature of 250 degrees; the varnish bath at 21 for a half hour at a temperature of ninety degrees; treatment in drum .22 revolving at one revolution per minute, was for four hours at a temperature of 280 degrees and the cores [7 were bathed .in the boiling wax at 24, .for twenty minutes. All temperatures mentioned are on the Fahrenheit scale.

This invention is capable of various'modiiications, applications and forms, without depart-' claims rather than to the specific description herein to indicate the scope of this invention.

I claim:

1. In an article of the character described, a wax-impregnated core of powdered iron and a tube of insulative material for carrying an electrical coil; said core being positioned at least in part within the tube and moveable therealong in-frictio na'l contact with the interior of the tube; the wax content of the core serving to station the core against accidental movement by causingv adhesion between the core and tube when thecore is at rest in engagement with the "tube and toease movement of the core when the core is intentionally shifted within the tube.

' 2QT-he article as-defined in claim 1, wherein the core and tube: are in threaded engagement.

'- N HARRY DANIELS.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,779,242 Laubi c. Oct. 21, 1930 2,138,741 Kronquest l Nov. 29, 1938 2,204,086 Kamenarovic June 11, 19.40 2,268,742 Daugherty Jan. 6, 1942 2,297,437 .Stapelfeldt Sept. 29, 1942 2,318,415 ,Patzschke' May 4, 1943 2,375,911 Foster May 15, 1945 2,402,903 Massey et .al June 25, 1946 2,460,773 Stimson Feb. 1, 1949 2,462,822 Wood Feb. 22, 19.49

FOREIGN PATENTS Number Country Date 48%,855 Great Britain May 11, 1938 

